/**
 * @author 汤奇
 * @version V1.0
 * @Project BookPro
 * @Package PACKAGE_NAME
 * @Description:
 * @Date 2022/7/27 21:02
 */
public class Test16 {
    public static void main(String[] args) {
        System.out.println(f(100));
    }
    private static long f (int n){
        if (n==1)
            return 1;
        return n+f(n-1);
    }
}
